Camouflage Coating Using Photochromic Microcapsules and Epoxy Resin

Using photochromism of a diarylethene, we demontrate an easy but highly effective coating method for a camouflage application. The photochromic ink is consisting of capsule type of photochromic pigments and UV curable epoxy resin, reversibly presenting colored pattern in response to ultraviolet (UV) light. The transmittance of the coatings was investigated based on concentrations of the photochromic microcapsules, we have found that 5 wt% of the microcapsules in epoxy resin is most appropriate for camouflage with background. Besides, in order to increase mechanical stability of the coating, thin protective layer including acrylate chemicals is further coated on the patterns. By taking advantage of bar-coating with various mask pattern, different patterns were successfully coated on various types of surfaces such as wood, glass, general concrete wall and even curved surfaces. Based on the coating method, camouflage application for an encryption quick response (QR) pattern was successfully demonstrated.